[FD] Yet another fork()/malloc() bomb in javascript + SIGILL in Chrome

2024-01-26 Thread Georgi Guninski
Searching the web for `javascript fork malloc bomb` returns results, e.g. [here][1]: and [here][2]: We got a javascript fork malloc bomb which crashed Chrome 121 on linux with SIGILL and about one in five runs the virtual machine freezes. SIGILL almost always is a sign of memory corruption :) On

[FD] Minor firefox DoS - semi silently polluting ~/Downloads with files (part 2)

2024-01-18 Thread Georgi Guninski
Minor firefox DoS - semi silently polluting ~/Downloads with files (part 2) Tested on: firefox 121 and chrome 120 on GNU/linux Date: Thu Jan 18 08:38:28 AM UTC 2024 This is barely a DoS, but since it might affect Chrome too we decided to disclose it. If firefox user visits a specially crafted

Re: [FD] cpio privilege escalation vulnerability via setuid files in cpio archive

2024-01-14 Thread Georgi Guninski
On Tue, Jan 9, 2024 at 12:45 AM Harry Sintonen wrote: > > On Mon, 8 Jan 2024, Georgi Guninski wrote: > > > When extracting archives cpio (at least version 2.13) preserves > > the setuid flag, which might lead to privilege escalation. > > So does for example tar. The s

[FD] cpio privilege escalation vulnerability via setuid files in cpio archive

2024-01-08 Thread Georgi Guninski
: Georgi Guninski # date: Mon Jan 8 07:28:28 AM UTC 2024 # tested on cpio (GNU cpio) 2.13 mkdir -p /tmp/1 cd /tmp/1 touch a chmod 4555 a echo -n a | cpio -ocv0 > a.cpio mkdir -p /tmp/2 cd /tmp/2 cpio -iv < ../1/a.cpio ls -lh /tmp/2/a #-r-sr-xr-x. 1 joro joro 0 Jan 8 09:10

[FD] Minor firefox DoS - semi silently polluting ~/Downloads with files

2023-09-05 Thread Georgi Guninski
This is barely a DoS, but since Chrome has explicit protection against it, we decided to disclose it. If firefox user visits a specially crafted page, then firefox may create many files in `~/Downloads`, The user is notified about this in a small dialog, but there is no option to stop the

[FD] Anomaly in Fedora `dnf update`: md5 mismatch of result

2023-08-15 Thread Georgi Guninski
In short, I found anomaly in Fedora 37 and would like to know if it is vulnerability. As root type in terminal: dnf update If there is kernel update, watch stdout and stderr for: ##On Mon Aug 14 05:33:29 AM UTC 2023 (2/6): kernel-6.4.10-100.fc37.x86_64.rpm1.2 MB/s | 140 kB 00:00

[FD] GNOME Files silently extracts setuid files from ZIP archives

2023-08-07 Thread Georgi Guninski
Affected: GNOME Files 43.4 (nautilus) on fedora 37 Description: If an user A opens in GNOME files zip archive containing `setuid` file F, then F will be silently extracted to a subdirectory of CWD. If F is accessible by hostile local user B and B executes F, then F will be executed as from user

[FD] Checking existence of firewalled URLs via javascript's script.onload

2023-04-21 Thread Georgi Guninski
There is minor information disclosure vulnerability similar to nmap in browser. It is possible to check the existence of firewalled URL U via the following javascript in a browser:

[FD] Checking existence of firewalled web servers in Firefox via iframe.onload

2023-04-21 Thread Georgi Guninski
In short in Firefox 112, it is possible to check existence of firewalled web servers. This doesn't work in Chrome and Chromium 112 for me. If user A has tcp connection to web server B, then in the following html: http://B; onload="load()" onerror="alert('error')" id="i1" /> the javascript

[FD] Insecure python cgi documentation and tutorials are vulnerable to XSS.

2023-03-21 Thread Georgi Guninski
Is there low hanging fruit for the following observation? The documentation of the python cgi module is vulnerable to XSS (cross site scripting) https://docs.python.org/3/library/cgi.html ``` form = cgi.FieldStorage() print("name:", form["name"].value) print("addr:", form["addr"].value) ```

Re: [FD] over 2000 packages depend on abort()ing libgmp

2022-10-16 Thread Georgi Guninski
On Fri, Sep 16, 2022 at 6:44 AM Matthew Fernandez wrote: > > > What is the security boundary being violated here? As a maintainer of > some of the packages implicated here, I’m unsure what my actionable > tasks are. The threat model(s) for my packages does not consider crashes > to be a security

[FD] over 2000 packages depend on abort()ing libgmp

2022-09-15 Thread Georgi Guninski
ping world libgmp is library about big numbers. it is not a library for very big numbers, because if libgmp meets a very big number, it calls abort() and coredumps. 2442 packages depend on libgmp on ubuntu20. guest3@ubuntu20:~/prim$ apt-cache rdepends libgmp10 | wc -l 2442 gawk crash:

[FD] sagemath denial of service with abort() in gmp: overflow in mpz type

2022-09-08 Thread Georgi Guninski
::numeric::pow_intexp(GiNaC::numeric const&) const () The non-minimal testcase === #sagemath code, copyright Georgi Guninski def binnk3u(n,k): return ( (n/k)**(k)) n1=(2*10**3);d0=29004853178239;n0=SR(log(n1)); tt=binnk3u(n0+d0-1,d0); print(&qu

[FD] Potential symlink attack in python3 __pycache__

2021-07-26 Thread Georgi Guninski
Potential symlink attack in python3 __pycache__ Not sure if this is vulnerability, but it looks like classical symlink attack. In python3, if a script in directory DIR1 does "import another", then python3 creates directory __pycache__ in DIR1 and puts some files in __pycache__. According to our

[FD] ipython3 may execute code from the current working directory

2021-07-23 Thread Georgi Guninski
Summary: under certain circumstances, ipython3 may execute code from the current working directory. This might be a problem if the current working directory is not trusted. python3 is safe. Tested on ubuntu 20. The following session illustrates it: joro@bialokote:~/tests/dir2$ pwd

[FD] Scope of Debian's /home/loser is with permissions 755, default umask 002

2020-11-12 Thread Georgi Guninski
On Debian /home/loser is with permissions 755, default umask 0022 (If you don't understand the numbers, this means a lot of files are world readable). On multiuser machines this sucks much. Question: How much sensitive data can be read on default install? Partial results: 1. mutt (text email

[FD] Short notes on qmail security guarantee

2020-05-22 Thread Georgi Guninski
From my blog: https://j.ludost.net/blog/archives/2020/05/21/short_notes_on_qmail_security_guarantee/index.html Short notes on qmail security guarantee Disclaimer: written in hurry, could be wrong. djb offers monetary bounty for verifiable qmail exploit, called "qmail security guarantee" [1].

[FD] pari/gp on debian stable allow arbitrary file write

2019-11-26 Thread Georgi Guninski
pari/gp on debian stable allow arbitrary file write pari/gp is CAS (computer algebra system). pari/gp version 2.9.1 on debian stretch and 2.11 on debian buster allow arbitrary file write and hence arbitrary code execution. poc: \\ a.gp \\ to run: \r a.gp

[FD] Minor security issue in punbb with SQLite

2019-11-12 Thread Georgi Guninski
From https://j.ludost.net/blog/archives/2019/11/11/minor_security_issue_in_punbb_with_sqlite/index.html Minor security issue in punbb with SQLite Georgi Guninski security advisory #76, 2019 Running punbb-master from https://github.com/punbb/punbb from Thu 07 Nov 2019 11:23:33 AM UTC

[FD] Should openssl accept weak DSA/DH keys with g = +/- 1 ?

2014-04-15 Thread Georgi Guninski
openssl accepts DSA (and probably DH) keys with g=1 (or g= -1). Both are extremely weak, in practice plaintext. g=1 works all the time g= -1 works about half the time in DSA (on vanilla openssl). Is there a MITM implication in this, e.g. can a MITM convince both parties that g=1 -- in this case